Gaseous electric discharge device



Get. 5, 1937. f w. FREITAG ET AL 2,094,647

GASEOUS ELECTRIC DISCHARGE DEVICE Filed uay'zs, 195e INVENTORS WingFreog YMorcn Reer A ORNEY Patented Oct. 5, 1937 UNITED STATES PATENTOFFICE GASEOUS ELECTRIC DISCHARGE DEVICE New York Application May 29,

1936, Serial No. 82,608

In Germany June 5, 1935 4 Claims.

The present invention relates to gaseous electric discharge devicesgenerally and more particularly the invention relates to such deviceshaving an elongated tubular container with electrodes mounted in theends thereof and a body of electrically conducting material extendingalong the discharge path between said electrodes to facilitate startingof the discharge between said electrodes similar to those disclosed inU. S. Patent 1,935,702, being the invention of Hans Ewest, Kurt Wiegandand Martin Reger.

In the patent referred to above the electrically conducting body, suchas a wire, helically coiled, when desired, is provided with aninsulating covering, such as a glass tube, or a plurality of closelyinterlocking short insulating tubes or rings surrounding the wire. Theends of the wire are not covered and are mounted adjacent the electrodesat opposite ends of the container. The object of the present inventionis to simplify and reduce the cost of the manufacture of gaseouselectric discharge devices of the above type. Another object of theinvention is to simplify the mounting of the starting element in thecontainer of the device. Further objects and advantages attaching to thedevice and to its use and operation will be apparent to those skilled inthe art from the following particular description.

In accordance with these objects the starting wire is provided with anenamel coating which is so thin that the flexibility of the coated wireis substantially the same as that of an uncoated wire. The coated wirethus easily adapts itself to the shape of a container in which it ismounted. The enamel has a, softening temperature lower than that of theglass of the container and the coated wire is mounted in said containerby heating said container to the softening temperature of the enamel tofrit the softened enamel onto the container wall. The enamel coating isapplied to the wire in the form of a paste which is then heated orbaked.

In the drawing accompanying and forming part of this specification anembodiment of the invention is shown, in which ig. l is a sideelevational view of a gaseous electric discharge lamp embodying theinvention, and

Fig. 2 is a side elevational, partly sectional view of one end of thedevice shown in Fig. 1.

Referring to Figs. 1 and 2 of the drawing the gaseous electric dischargelamp consists of an elongated tubular container I having an electrode 4,5 sealed into each end thereof. Said container I has a gaseousatmosphere therein consisting of a rare gas, a common gas, a metalvapor, a mixture of gases, or a mixture of gases and vapors, such asneon, or a mixture of argon and mercury vapor. The starting andoperating mixtures of gases well known in the art are used, whendesired. Each of said electrodes 4, 5 comprises a filament 4, such as atungsten filament, wrapped around a curved rod 5 of material having highelectron emissivity, when heated. When desired, said rod 5 consists of acompacted, sintered mixture of high melting point metal, such astungsten, and electron emitting material, such as barium oxide andstrontium oxide. Said filament 4 is attached to the current leads 2 and3 sealed into said container I.

A helically coiled wire 6 extends along the discharge path between saidelectrodes 4, 5. Said wire 6 has a thin coating l of enamel thereonwhich has a lower softening temperature than that of the glass of saidcontainer I. A softening temperature of about 300 C. is desirable forthe enamel coating l. The enamel coating l is fritted to the insidesurface of the container I by heating said container or spots thereon tothe softening temperature oi the enamel coating l. The wire 6 is thussupported in said container I. The coating l is less than a millimeterthick and is preferably about 0.1 mm. in thickness so that it isflexible and easily accommodates itself to the shape of curvedcontainers as well as the straight container illustrated in Fig. 1.

The ,ends 8 of the helically coiled wire E project beyond the coating l.When the starting potential is applied across the terminals of the lampa glow discharge takes place between each end 8 and the electrode` 4, 5adjacent thereto which facilitates the starting of the main dischargebetween said electrodes 4, 5. A condenser discharge also takes placebetween the helically coiled wire 6 and the electrodes 4, 5 whichlikewise facilitates the starting of the main discharge between saidelectrodes 4, 5. In certain instances the condenser discharge alone issufficient to facilitate the starting of the main discharge and in suchcases the ends 8 of the wire 6 are covered with the insulating enamelcoating l, when desired.

While we have shown and described and have pointed out in the annexedclaims certain novel features ofthe invention, it will be understoodthat various (omissions, substitutions and changes in the forms anddetails of the device illustrated and in its use and operation may bemade by those skilled in the art without departing from the broad spiritand scope of the invention, for

example, the wire 6 is connected to the current lead of one or both ofsaid electrodes 4, 5 when desired, the wire 6 is mounted in other than astraight line in said container l, when desired, and other types ofelectrodes, such as the Hull electrode, are used, when desired.

What we claim as new and desire to secure by Letters Patent of theUnited States, is:-

1. A gaseous electric discharge device comprising a container,electrodes sealed therein, a gaseous atmosphere therein, a body ofelectrically conducting material extending along the discharge pathbetween said'electrodes and a coating of enamel on said body.

2. A gaseous electric discharge device ycomprising a glass container,electrodes sealed therein, a gaseous atmosphere therein, a. body ofelectrically conducting material extending along the discharge pathbetween said electrodes and a coating of enamel on said body, saidenamel coating having a lower softening temperature than said glasscontainer and being fritted thereto.

3. A gaseous electric discharge device comprising a container,electrodes sealed therein, a gaseous atmosphere therein, a body ofelectrically conducting material extending along the discharge pathbetween said electrodes and a thin, flexible coating of enamel on saidbody.

4. A gaseous electric discharge device comprising a container,electrodes sealed therein, a gaseous atmosphere therein, a flexible bodyof electrically conducting material extending along the discharge pathbetween said electrodes and a thin, flexible coating of .enamel on saidbody.

WILLY FREITAG. MARTIN REGER.

